With constant development of a software-defined networking (SDN)/OpenFlow network, a scenario in which an SDN/OpenFlow network and a conventional IP network will coexist in a period of time in the future. The OpenFlow network is one type of SDN network in which the OpenFlow is used as a protocol. How to implement communication between an OpenFlow network/device and a conventional IP network/device in a case in which an existing conventional IP network/device is not modified is an important subject in the SDN/OpenFlow network.
An existing solution is an edge OpenFlow switch exchanges a conventional IP network control plane protocol message with an IP switch/router directly connected to the edge OpenFlow switch, for example, an open shortest path first (OSPF) link state update message (LSU), a Border Gateway Protocol (BGP) update message, or a Label Distribution Protocol (LDP) broadcast message. After receiving the conventional IP network control plane protocol message sent from the IP switch/router, the edge OpenFlow switch encapsulates an entire Transmission Control Protocol/Internet Protocol (TCP/IP) data packet that carries the message into a Packet In message and reports the Packet In message to an OpenFlow controller (OFC). After receiving the Packet In message, the OFC parses the Packet In message to obtain valid information and sends the valid information obtained by means of parsing to a corresponding IP network control plane protocol module for processing. To enable an OpenFlow system, which includes the OpenFlow switch and a corresponding controller, to send the conventional IP network control plane protocol message to the IP switch/router directly connected to the OpenFlow system, an IP network control plane protocol module of the OFC first constructs a conventional IP network control plane protocol message, the OFC then encapsulates the message into a Packet Out message, the OFC then sends the encapsulated Packet Out message to the edge OpenFlow switch, and the edge OpenFlow switch extracts the corresponding conventional IP network control plane protocol message from the received Packet Out message and forwards the conventional IP network control plane protocol message from a physical port specified by the Packet Out message to the IP switch/router directly connected to the edge OpenFlow switch.
In the foregoing processing process, for the IP network control plane protocol message encapsulated into the Packet In message/Packet Out message, the IP network control plane protocol message is generally carried on a TCP layer. In this way, the OFC needs to process a TCP/IP protocol stack twice, but it is extremely difficult to process two layers of TCP/IP protocol stacks. As a result, extra overheads are brought to the OFC, and processing a critical event using a limited computing resource by the OFC is affected.